The class of polymers of carbon monoxide and olefin(s) is well known in the art. Brubaker, U.S. Pat. No. 2,495,286, produced such compositions of relatively low carbon monoxide content in the presence of free radical initiators, e.g., peroxy compounds. G.B. 1,081,304 discloses such polymers of higher carbon monoxide content produced in the presence of an alkylphosphine complex of palladium salts as catalyst. Nozaki extended the reaction to produce linear alternating polymers in the presence of arylphosphine complexes of palladium moieties and certain inert solvents. See, for example, U.S. Pat. No. 3,694,412.
More recently, the class of linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon has become of greater interest in part because of the greater availability of the polymers. These linear alternating polymers, now known as polyketones or polyketone polymers, arc also produced by more recent processes which are illustrated by a number of published European Patent Applications including 121,965, 181,014, 213,671 and 257,663. These processes typically involve the use of a catalyst composition formed from a Group VIII metal selected from palladium, cobalt or nickel, the anion of a strong non-hydrohalogenic acid and a bidentate ligand of phosphorus, arsenic, antimony or nitrogen.
The resulting polymers are relatively high molecular weight, thermoplastic materials having established utility in the production of shaped articles produced by methods such as extrusion and injection molding which are conventional for thermoplastics. When the production of the polyketone polymers is conducted under relatively constant conditions of temperature, pressure and feed composition the polymers which result have a rather narrow molecular weight distribution. This narrow molecular weight range is desirable for many applications of the polyketone polymers. The molecular weight distribution is described by the term "Q" which is the quotient of the weight average molecular weight (M.sub.w) and the number average molecular weight (M.sub.n). For the polyketone polymers produced according to the above published European Patent Applications, a typical value for Q will be from about 2.0 to about 2.3. For some polymerizations conducted over a long reaction time or on a technical scale the value for Q may be (rom about 2.3 to about 2.5, reflecting a somewhat wider molecular weight distribution.
For other applications however, a somewhat broader molecular weight range may be desirable because of processing considerations. A polymer having a wider molecular weight range will normally exhibit better melt flow properties including better melt strength and lower heat of friction during extrusion. It would therefore be of advantage to provide polyketone polymers having a wider range of molecular weights.